Boiler-feed-water heater



March 4, 1930. J. N. WYNDHAM ETAL 1,749,654

BOILER FEEDWATER HEATER Filed March 31. 1928 f v 4 f a 4 1 2 11?}, v 10- 1a 1% 15 16 Patented Mar. 4, 1930 UNITED STATES PATENT OFFICE JAMES NEWBY WYNDHAM AND STEPHEN LEYSHON WYNDHAM, OF CARDIFF, WALES BOILER-FEED-WATER HEATER Application filed March 31, 1928, Serial No. 266,391, and in Great Britain July 29, 1927.

I This invention relates to the type of boiler feedwater heater embodying steam-heating tubes or coils or equivalent with which the feedwater contacts. i

We provide a heater of this type, having at least one auxiliary conduit in circuit with the main body or casing of the heater, and means whereby the feedwater entering said body or casing from the feed main is utilized to set up a return flow through said conduit (hereinafter termed the return pipe). The'arrangement ensures a repeated circulation ormultiflow of the feedwater in the heater and acon sequential increase in heating efiiciency, without structural complication, the apparatus being substantially as simple in construction as a uni flow heater. 1

' Said'means may take the form of an inlet box having two, preferably aligned, nozzles through which the feedwater enters the body of the heaterfrom the feed main and between which the return pipe opens into the inlet box, these nozzles both tapering inwards in the direction of flow.

Preferably thebody of the heater consists of a tube to one flanged end of which is attached an inlet box having nozzles as aforesaid, and to the other flanged end of which is attached an outlet box provided witha removable door or closure supporting bent steam-heating tubes that extend into the body. The return pipe for the feedwater is arranged below the body and jointed at its ends to tubular elbows extending from said inlet and outlet boxes.

' If desired, a by-pass around the heater may be provided so that the heating tubes may be withdrawn, for cleaning or other purposes, without stopping the pumps."

' By way of example, one constructional form of feedwater heater embodying the before mentioned and other features of our invention is illustrated, in longitudinal section, on the accompanying drawing to which reference will now be made.

7 The heater comprises a horizontally arranged body 1, a feedwater inlet box 2, a feedwater outlet box 3, steam-heating coils 4 located in the body, and a return-flow pipe 5. Conveniently, the body is formed from a steel or copper tube and is say six or eight inches in diameter and about six feet long, but it may be made of cast iron or other suitable metal or material. It is flanged at the ends to receive the metal inlet and outlet boxes 2 and 3, which have connections 6 and 7 to joint into the main line of feed pipes on the delivery side of the feed pumps (not shown). The feed outlet connection 7 is shown arranged above the heater body.

A door or closure 8 removably fitted to the outlet box 3 in direct line with the body 1 of the heater, supports the heating coils 4 each of which is formed of a tube bent upon itself as many timesas possible while allowing it to pass freely into the heater body and have both its ends jointed, as shown, to the door. The number of coils 4 varies according to the degree of heat required. For instance, there may be five coils disposed side by side, the two outer coils each having four limbs while the remainder each have six limbs.

Fitted over the door or closure 8 is a steam distributing chest 9 having a partition 10 to separate one end of each heating tube 4 from its other end and thereby provide a steam inlet 11 and a steam outlet 12 to and from the tubes.

In the inlet box 2 through which the feedwater enters the heater there is formed a nozzle 13 tapering down from the diameter of the feed pipe (not shown) to an inch or so less, and aligned with this nozzle is a second nozzle 14 having its large end open towards the first. A branch 15 formed integral with the inlet box extends between the two nozzles and is flanged, at 16, to receive one flanged end of a tubular-elbow 17; a similar tubular elbow 18 extends from the outlet box 3 at the other end of the heater, and the return pipe 5 is connected between these elbows.

During the operation of the heater the feedwater therein for the time being is heated by contact with the tubes 4 through which exhaust or live steam is passed. Naturally the hottest part of this water rises to the top of the casing 1 whereas the coldest water gravitates to the bottom of said casing and to the return pipe 5. Now, as each fresh quantity of feedwater is admitted to the heater through the inlet box 2 and under the action of the feed pump, some of the hottest water is displaced from the upper part of the casing 1 through the feed outlet connection 7 towards the boiler. At the same time some of the coldest water at the bottom of the heater is, by reason of the nozzles 13 14, drawn back through the return pipe 5 and again passed through the heater. In passing through the nozzle 13 the teedwater entering the heater from the main has its velocity increased, and in passing through the second nozzle 14 it induces a return flow through the pipe 5 of some of the water (the coldest) already in the apparatus. Thus, the heater operates as an eflicient multi-flow heater, only thevery hottest water at the top passing to the outlet 7 at each stroke of the feed pump. The ratio capacity of the heater to the pump governs the number of flows. 7

As the steam-heating tubes 4 are solely attached to the door 8 they can be removed as a unit with the latter, thus facilitating the work of cleaning the tubes and the interior of the heater body 1. Expansion or contraction of the tubes due to change of temperature is taken up by the bends and leaky joints are thus avoided. I

Although one embodiment of the invention has been herein described, it is obvious that modifications may be, made. For example, the nozzles 13 14 instead of being cast integral with the inlet box 2 may be separate therefrom and removably fitted in position.

If desired, the connection 7 may be equipped with a thermometer and/or anair extraction cock. Moreover, the returnfiow conduit may be formed integral with the main heater casing.

We claim v 1.v In a boiler teedwater heater, the com bination of a casing forming a main conduit for the passage of the teedwater to the boiler, means for heating the feedwater in the casing, atleast one auxiliary conduit in circuit with the casing, and means whereby the feedwater admitted to the casing is utilized to set up a return flow-through the auxiliary conduit. 7

2. In a boiler feedwater heater, the combination of a casing forming a main conduit for the passage of the feedwater to the boiler,

means in the casing for heating the feedwater, spaced nozzles constituting the inlet to the casing, and a return flow conduit leading fromv the delivery end of the casing to the space between the nozzles, whereby a multifiow of the feedwater in the heater; will be obtained.

3. A boiler feedwater heater comprising a tubular casing forming a main conduit for the passage of feedwater to the boiler, an inlet box at one end of the casing, nozzles in the inlet box, an outlet box at the other end of the casing, steam-heating'coils extending into the casing, and a return flow conduit connected between the inlet and outlet boxes.

4:. A boiler feedwater heater comprising a tubular caslng, an inlet box at one end of the casing, nozzles in the inlet box, an outlet box at the other end of the casing, a removable door fitted to the outlet box, coiled steamheating tubes carried by the door and pro-' casing, nozzles in the inlet box, an outlet box 7 at the other end of the casing, steam-heating coils extending into the casing, tubular elbows on the inlet and outlet boxes, and a pipe connecting the tubular elbows. y

'6. A boiler feedwate r heater comprising a tubular casing, an inlet box at one end ofthe casing, nozzles in the inlet box, an outlet box at the other end of the casing, a removable door fitted to the outlet box, coiled steamheating tubes carried by the door and pro.- jecting into the casing, tubular elbows on the inlet and outlet boxes, and a pipe connecting the tubular-elbows. r

7 A boiler feedwater heater comprising a tubular casing, an inlet box at one end of the casing, nozzles in the inlet box, an outlet box atthe other end of the casing, steamhea-ting coils extending into the casing through the outlet box, a steam-distributing chest for the coils fitted to the outlet box, and a return flow conduit connected between the inlet and outlet boxes.

8. A boiler feedwater heater comprising a tubular casing, an inlet box atone end of the casing, nozzles in the inlet box, an outlet box atthe other end of the casing, a removable door fitted to the outlet box, coiled steain heating tubes carried by the door and proj ecting' into the casing, a steam-distributing chest for the coils fitted over the door, and at least one return flow conduit connected be.-

let box, and a pipe connecting the tubular el- 7 bows, said elbows and said pipe forming a passage between the inlet and outlet boxes.

10. A boiler feedwater heater comprising a tubular casing, an inlet box at one end of the casing, spaced nozzles in the inlet box, an outlet box at the other end of the casing, a removable door fitted to the outlet box, coiled steam-heating tubes carried by the door and projecting into the casing, a steam-distributing chest for the coils fitted over the door, a tubular elbow on the inlet box communicating with the latter between the spaced nozzles, a tubular elbow 0n the outlet box, and a pipe connecting the tubular elbows.

In testimony whereof We affix our signatures.

JAMES NEWBY WYNDHAM.

STEPHEN LEYSHON WYNDHAM. 

